fix(joinir): Phase 287 P2 - Pattern6 nested loop latch overwrite fix

Fix infinite loop in Pattern6 (nested loop minimal) caused by main→loop_step
overwriting k_inner_exit→loop_step latch values.

Root cause: JoinIR main entry block was incorrectly treated as BackEdge,
causing it to overwrite the correct latch incoming values set by the true
back edge (k_inner_exit → loop_step).

Solution:
- Restrict latch recording to TailCallKind::BackEdge only
- Treat only MAIN's entry block as entry-like (not loop_step's entry block)
- Add debug_assert! to detect double latch set in future

Refactoring:
- Extract latch recording to latch_incoming_recorder module (SSOT)
- Add boundary.loop_header_func_name for explicit header identification
- Strengthen tail_call_classifier with is_source_entry_like parameter

Tests: apps/tests/phase1883_nested_minimal.hako → RC:9 (was infinite loop)
Smoke: 154/154 PASS, no regressions

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
This commit is contained in:
2025-12-27 09:39:29 +09:00
parent bbfc3c1d94
commit a04b48416e
20 changed files with 401 additions and 171 deletions

View File

@ -308,6 +308,15 @@ pub struct JoinInlineBoundary {
/// Used to track which PHI corresponds to the loop variable.
pub loop_var_name: Option<String>,
/// Phase 287 P2: Loop header function name (SSOT)
///
/// Merge must not guess the loop header function from "first non-main non-continuation".
/// For loop patterns, set this explicitly (typically `"loop_step"`).
///
/// - `Some(name)`: Merge uses this as the loop header function.
/// - `None`: Legacy heuristic remains (for backwards compatibility).
pub loop_header_func_name: Option<String>,
/// Phase 228: Carrier metadata (for header PHI generation)
///
/// Contains full carrier information including initialization policies.
@ -435,6 +444,7 @@ impl JoinInlineBoundary {
expr_result: None, // Phase 33-14: Default to carrier-only pattern
jump_args_layout: JumpArgsLayout::CarriersOnly, // Phase 256 P1.12
loop_var_name: None, // Phase 33-16
loop_header_func_name: None, // Phase 287 P2
carrier_info: None, // Phase 228: Default to None
continuation_func_ids: Self::default_continuations(),
exit_reconnect_mode: ExitReconnectMode::default(), // Phase 131 P1.5: Default to Phi
@ -482,6 +492,7 @@ impl JoinInlineBoundary {
expr_result: None, // Phase 33-14
jump_args_layout: JumpArgsLayout::CarriersOnly, // Phase 256 P1.12
loop_var_name: None, // Phase 33-16
loop_header_func_name: None, // Phase 287 P2
carrier_info: None, // Phase 228
continuation_func_ids: Self::default_continuations(),
exit_reconnect_mode: ExitReconnectMode::default(), // Phase 131 P1.5: Default to Phi
@ -546,6 +557,7 @@ impl JoinInlineBoundary {
expr_result: None, // Phase 33-14
jump_args_layout: JumpArgsLayout::CarriersOnly, // Phase 256 P1.12
loop_var_name: None, // Phase 33-16
loop_header_func_name: None, // Phase 287 P2
carrier_info: None, // Phase 228
continuation_func_ids: Self::default_continuations(),
exit_reconnect_mode: ExitReconnectMode::default(), // Phase 131 P1.5: Default to Phi
@ -596,6 +608,7 @@ impl JoinInlineBoundary {
expr_result: None, // Phase 33-14
jump_args_layout: JumpArgsLayout::CarriersOnly, // Phase 256 P1.12
loop_var_name: None, // Phase 33-16
loop_header_func_name: None, // Phase 287 P2
carrier_info: None, // Phase 228
continuation_func_ids: Self::default_continuations(),
exit_reconnect_mode: ExitReconnectMode::default(), // Phase 131 P1.5: Default to Phi
@ -650,6 +663,7 @@ impl JoinInlineBoundary {
expr_result: None, // Phase 33-14
jump_args_layout: JumpArgsLayout::CarriersOnly, // Phase 256 P1.12
loop_var_name: None, // Phase 33-16
loop_header_func_name: None, // Phase 287 P2
carrier_info: None, // Phase 228
continuation_func_ids: Self::default_continuations(),
exit_reconnect_mode: ExitReconnectMode::default(), // Phase 131 P1.5: Default to Phi
@ -711,6 +725,7 @@ impl JoinInlineBoundary {
expr_result: None, // Phase 33-14
jump_args_layout: JumpArgsLayout::CarriersOnly, // Phase 256 P1.12
loop_var_name: None, // Phase 33-16
loop_header_func_name: None, // Phase 287 P2
carrier_info: None, // Phase 228
continuation_func_ids: Self::default_continuations(),
exit_reconnect_mode: ExitReconnectMode::default(), // Phase 131 P1.5: Default to Phi
@ -767,6 +782,7 @@ mod tests {
expr_result: Some(ValueId(10)),
jump_args_layout: JumpArgsLayout::ExprResultPlusCarriers,
loop_var_name: None,
loop_header_func_name: None,
carrier_info: None,
continuation_func_ids: JoinInlineBoundary::default_continuations(),
exit_reconnect_mode: ExitReconnectMode::default(),

View File

@ -98,6 +98,7 @@ impl JoinInlineBoundaryBuilder {
expr_result: None,
jump_args_layout: JumpArgsLayout::CarriersOnly,
loop_var_name: None,
loop_header_func_name: None, // Phase 287 P2
carrier_info: None, // Phase 228: Initialize as None
continuation_func_ids: JoinInlineBoundary::default_continuations(),
exit_reconnect_mode: ExitReconnectMode::default(), // Phase 131 P1.5
@ -184,6 +185,14 @@ impl JoinInlineBoundaryBuilder {
self
}
/// Phase 287 P2: Set loop header function name (SSOT)
///
/// If omitted for loop patterns, `build()` defaults it to `"loop_step"` when `loop_var_name` is set.
pub fn with_loop_header_func_name(mut self, name: Option<String>) -> Self {
self.boundary.loop_header_func_name = name;
self
}
/// Set expression result (Phase 33-14)
///
/// If the loop is used as an expression, this is the JoinIR-local ValueId
@ -200,6 +209,14 @@ impl JoinInlineBoundaryBuilder {
boundary.expr_result,
boundary.exit_bindings.as_slice(),
);
// Phase 287 P2: Default loop header function name for loop patterns.
// If a pattern sets loop_var_name, it must have a loop header function.
if boundary.loop_var_name.is_some() && boundary.loop_header_func_name.is_none() {
boundary.loop_header_func_name =
Some(crate::mir::join_ir::lowering::canonical_names::LOOP_STEP.to_string());
}
boundary
}